PITTSBURGH — A green roller coaster twists above the entrance to the Children's Museum of Pittsburgh. But this attraction isn't for human riders — the coaster's cars are filled with plants and a solar panel that triggers the ride to stop and start.

The coaster is one of 11 "BigBot" robotic art installations in a two-week citywide celebration of robotics, dubbed Robot 250 to coincide with Pittsburgh's 250th anniversary.

"It bends the idea of what robotics is about and who it's for," said Illah Nourbakhsh, an associate professor at Carnegie Mellon University's Robotics Institute and one of the originators of the Robot 250 idea. He hopes the project shows that rather than just being for industrial automation or tinkering engineers, robots can give everyday people a new way to express themselves.

The prelude to Robot 250 included workshops for dozens of teachers so that kids and adults could create their own robots. The results were robots big and small, complex and simple: One woman used a Polaroid camera and other parts to create a robot that took pictures of cars speeding in front of her home. One group made a conceptual robot that would automatically salt the city's bridges in the winter, to encourage more people to walk them.

Kyle Buzard, 11, worked with several of his seventh-grade classmates to create robotic flower petals decorated with images to represent good — healthy things like fruits and vegetables — and bad, such as alcohol abuse or drugs. "We wanted to build a robot that would show how we could help the community," Kyle said.

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